An autopilot is a system that controls the trajectory of an aircraft without a human pilot's constant input or ‘hands-on’ control. Three types of autopilots are commonly available—single-axis autopilots, two-axis autopilots, and three-axis autopilots. Single-axis autopilots control an aircraft's roll or rotation about the aircraft's roll axis. Single-axis autopilots typically control an aircraft's ailerons. Two-axis autopilots control an aircraft's pitch or rotation about the aircraft's pitch axis in addition to an aircraft's roll. Two-axis autopilots typically control independently an aircraft's ailerons and elevator or stabilator. And three-axis autopilots control an aircraft's yaw or rotation about the aircraft's yaw axis in addition to an aircraft's roll and pitch. Three-axis autopilots typically control independently an aircraft's rudder, ailerons and elevator.
Because autopilots automate one or more aspects of controlling an aircraft during flight, autopilots relieve human pilots of continually holding an aircraft's flight controls, such as an aircraft's control yoke or stick, which can be very tiring on long flights. When a pilot is allowed to divert some of his/her attention away from some of the aircraft's flight controls, the pilot can focus on other aspects of the flight, such as plotting a new course to avoid an approaching storm, and/or rest. Thus, autopilots frequently enhance flight safety by reducing a pilot's workload and fatigue. Autopilots can also improve flight efficiency in terms of time and fuel.
Many commercial jet airliners and corporate aircraft with five or more seats have an autopilot that a human pilot can use while flying the aircraft. Unfortunately, though, many smaller, private, general aviation aircraft do not have an autopilot. Often this is because an autopilot is expensive and complex to purchase and install in an aircraft. For older aircraft such cost may exceed the value of the aircraft.
Thus, there is a need for a portable, low-cost autopilot that may be releasably mounted in an aircraft, used during a flight, and then, if desired, removed from the aircraft for use in another aircraft. Furthermore, there is a need for an autopilot that may be releasably mounted in a variety of different aircraft types and models.